package lv.abvs.ante;import java.io.IOException;import javax.servlet.http.*;import com.google.appengine.api.users.User;import com.google.appengine.api.users.UserService;import com.google.appengine.api.users.UserServiceFactory;@SuppressWarnings("serial")public class GuestbookServlet extends HttpServlet {    public void doGet(HttpServletRequest req, HttpServletResponse resp)              throws IOException {        UserService userService = UserServiceFactory.getUserService();        User user = userService.getCurrentUser();        if (user != null) {            resp.setContentType("text/plain");            resp.getWriter().println("Hello, " + user.getNickname());        } else {            resp.sendRedirect(userService.createLoginURL(req.getRequestURI()));        }    }}